The presence of metal from ash producing lubricants is found in automotive emissions and needs to be reduced to meet regulations and to improve efficiency of engines. Engine oils contain detergents and anti-wear agents which typically contain zinc, sulfur, phosphorous, calcium and/or magnesium which help prevent wear in the engine to prevent deposit formations and neutralize acids that form in the oil from the combustion process. The presence of sulfonated ash in the engine exhaust is thought to be a source of particulates which plug diesel particulate filters, thus reducing the filter's efficiency, making regeneration difficult and contributing to the reduced life of the filter. Regulations for maximum level of SAPS (e.g., sulfonated ash, phosphorous and sulfur) levels in the engine oil has created challenges to discover substantially ash free components. Therefore, the use of lubricants with substantially ash free components are needed to meet regulations and reduce emission; however, such components typically, as noted above, are useful in protecting the engine also. Lubricant compositions, in particular, crankcase motor oils are needed that produce low ash to ashless lubricants.
The use of controlled release gels as a means to release lubricant additive over time has been shown to effectively provide additive chemistry to the lubricant thus improving the lubricant's performance efficiency. The controlled release gels based on overbased metal chemistry is described in U.S. Pat. No. 6,843,916B, U.S. Pat. No. 7,000,655, U.S. Ser. No. 10/196,441, U.S. Ser. No. 10/603,644, U.S. Ser. No. 11/506,298, U.S. Ser. No. 11/092,403, U.S. Ser. No. 11/045,815 and U.S. Ser. No. 11/557,508 each incorporated by reference herein. The gels with metal producing components typically have good physical characteristics and good delivery over time of additives as specified by total base number (TBN) per weight of gel into the lubricant. Ash free gels eliminate the ash metal but generally require more gel because TBN's ashless gel components are lower than typical ash containing overbased detergents.
It is desirable to have a lubricant composition that has reduced levels of SAPS as well as preventing wear and deposit formation in the engine.
It is desirable to have a class of controlled release gels that has a reduced amount of ash producing components but still contains TBNs at a level found in ash containing formulations.
It is desirable to have a low ash producing controlled release gel with a (increased) level of TBN delivery per weight of gel.
The present invention provides for the use of a controlled release gel with a controlled level of ash producing components for delivery of additives into lubricants.
The present invention provides for a controlled release gel that has a reduced amount of ash producing component while maintaining good TBN density and good physical gel characteristics as well as reduced emissions.